Conventionally, there is known a method of connecting a computer (product sales system) of a product manufacturing company and a computer of a product purchase company via a communication line and sending a sales price of a product from the computer of the product manufacturing company to the computer of the product purchase company to advise the sales price.
In a material sales system for supplying a material from a material supply company to a product manufacturing company and manufacturing a product in the product manufacturing company using the material, a material price is generally arranged in advance between the material supply company and the product manufacturing company. Usually, the product manufacturing company requires the material from the material supply company meet a quality within a specific specification.
If a material meets the required specification, the material supply company often sells the material at a high price as a first grade product. If a material does not meet the required specification, the material supply company often sells the material at a low price as an off-spec product.
However, a specification that the product manufacturing company requires of the material supply company is not always a specification that is actually needed in manufacturing a product in many cases. In such a case, the material supply company spends production costs, which are essentially unnecessary, in order to observe the specification. As a result, a material price increases.
In addition, for example, if a material meets 99% of a required specification but does not meet the remaining 1% of the required specification, the material supply company can only sell the material at a low price as a second grade product, that is, an off-spec product, for an application that requires low performance. However, the material can actually be used in the product manufacturing company without any significant problem in many cases. In such a case, the material supply company suffers a significant damage.
On the other hand, even if the material supply company tries to meet a required specification, it may be impossible to inspect all materials. Thus, an inappropriate material may be sold to the product manufacturing company and cause a problem in manufacturing a product. In such a case, the product manufacturing company suffers detriment despite the fact that it pays a price of a first grade product, and a trouble occurs between the companies.
Such a trouble is processed between a person of the product manufacturing company and a person of the material supply company by telephone communication or the like, which takes a long time.